Improvement in thimbles for steam-boilers



f PATENT OFFICE.

SAMUEL WETHERED, OF BALTIMORE, MARYLAND.

IMPROVEMENT IN THlMBlLES FOR STEAlVl-BC-DILERS.

Specification forming part of Letters Patent No. 43,938, da' ed August23, 1864.

To all whom it may concern: I

Be it known that I, SAMUEL WETHERED, of Baltimore, Baltimore county,State of Maryland, have invented a new Device for Protecting the Ends ofFlues; and I do hereby declare that the following is a full, clear, andexact description thereof, reference being had to the accompanyingdrawings, making a part of this specification, in which- Figure 1 is aperspective viewof my invention. Figure 2 is an end view, and Fig.'3represents a longitudinal section of my inven p of the boilers orsuperheaters, as it Will be tion applied to the end of a llue or tube.

Similar letters of reference indicate corre-l sponding parts in thethree gures.

The object of my invention is to protect the ends of tubes or Ilues intubular steam-boilers and superheaters from rapid destruction, causedchiefly by the intense heat to which they are subjected, and to effectthis object by means of self-adjusting devices applied to the tubes,substantially as will be hereinafter described.

To enable others skilled in the art to make and use my invention, I willdescribe its construction and operation.

rIhe device which I have invented consists of a cylindrical or tubularportion, al, which vice will hold itself in place, and may be removed atpleasure for cleaning out the soot and cinders from the ue. On one endof this split cylinder a a circular iange, c, is formed or applied inany suitable manner, and on the inside surface of this flange an annulargroove or depression, d, is formed, the object of which is to receivethat portion of the flue-tube which projects outside, or from theoutside surface of the flue-sheet, as shown in Fig. 3.

' In'that class of boilers where the heat is applied outside of theflue-tubes the flanged thimbles which I have above described will bepassed over the tubes and the flanges drawn down snugly against thesheets, and, if desired or found necessary, cement and bolts,

or both, may be employed to keep the thimbles in place.

In the application of my thimbles to this class of boilers the groove ordepression d will of course be formed on the outer surface-of the flangec, in order to allow the end of the thimble to fit snugly against thetube-sheet.

I do not confine the use of my invention to the tubes of steam-boilersexclusively, as the same may be applied to the tubes of superheaters andwherever it can be advantageously used; nor do I confine its use to oneend tional thickness of metal, which can be readily removed and renewedwhen worn out.

The distinguishing characteristic of my invention is this: I constructeach tube with a short auxiliary flanged tube at one or both ends at thetime that I insert the tubes in the flue sheet or sheets. These shorttubes are made of durable metal or re-proof material. They aredisconnectible from the tubes proper in the event of burning out. Thisis effected without disturbing the tubes proper. These auxiliary tubessave the tubes proper from burning out so as to require repairing. Theseauxiliarytubes, by being exposed to the heat or fire direct, expand to agreater extent than the tubes proper, and therefore leaks at the jointswill not be experienced. These auxiliary tubes, when at each end of thetubes proper, increase the intensity of the circulating heat, as thecurrent is slightlyr retarded between the ends of the auxiliary tubes.This, however, does not decrease the draft, as the sudden escape of theretarded current causes an increased draft at the aft end of the boiler.

My invention has no reference to repairing tubes, of boilers after theirends have been burnt out or caused to spring. It relates exclusively tothe original or iirst insertion of A device for protecting the ends offlues of -steam-boilers superheaters, Svc., constructed of a split tube7a., and a grooved face-flange, c, substantially as and for the purposesherein described.

SAMUEL WETHERED.

Witnesses:

N. G. PENNIMAN, SAML. D. TOY.

